216 Field Columbian Museum — Zoology, .Vol. V. 



Body deep, compressed; profile with a quite even curve, except in 

 males with the nuchal hump; mouth moderate; maxillary 2^ in 

 head ; mandible 2 l / 2 ; jaws equal, or the lower the longer in males ; outer 

 series of teeth conical, enlarged; lips moderately thick, the lower with 

 a frenum; preorbital 2;"; in head; postorbital 2^; interorbital very 

 convex, 2 X / A in head; diameter of eye \)4, in head; cheeks with 5 rows 

 of scales; eighth dorsal spine 2-f in head; last dorsal spine 2 T * ; the 

 middle rays of dorsal and anal produced, reaching in the male slightly 

 past the middle of the caudal fin, in female to about middle of caudal 

 fin; pectoral fin 2^ in head; ventral with their rays produced, their 

 tips reaching third anal spine ; ventrals slightly longer than the head ; 

 caudal fin rounded; least depth if in head; length of caudal pe- 

 duncle if in the depth. 



Color olivaceous, 5 indistinct dark bars on the posterior half of the 

 body; a black caudal spot, slightly more than half above the lateral 

 line; many small. white spots on sides, being most numerous on head 

 ventral surface, head and caudal peduncle; white spots on vertical 

 fins, being most numerous on the base of soft dorsal and anal, and on 

 caudal fin; ventrals black or very dark; pectorals light. Many half 

 grown and adult individuals with posterior half of body and ventral 

 region below base of pectoral fin black. Males of this species, 7 

 inches long and over, have a well developed nuchal hump. Length 

 about 1 2 inches. 



At La Cruz I succeeded in catching a large number of adults of 

 this species. Many of the smaller males and all of the females had no 

 nuchal hump. All of the larger males had the hump more or less 

 developed. The sexual organs of the males were undeveloped. The 

 ovaries of the females of some specimens were a little more developed 

 than in others, but none were at all near the spawning period, and 

 there was no evidence that would indicate the approximate time of 

 spawning. 



204. Cichlasoma rectangulare (Steindachner). 



Acara rectangularis Steindachner, Chromiden Mexicos, 1864, 1; 

 Mexico. 



Cichlasoma rectangulare Jordan & Evermann, Bull. 47, U. S. Nat. 

 Mus., 1896, 1 5 1 5. 



Distribution unknown. 



Head 3^4", depth 2^; D. xvi, 13; A. iv, 11; scales 21-33. Body 

 moderately elongate, the back considerably arched; profile depressed 

 before the eye , which is in the middle of the head ; maxillary reaching 

 front of eye ; outer teeth large, somewhat canine-like ; lower lip with a 

 frenum; eye 4! in head; preorbital 3^ in head; 7 rows of scales on 



